The developers of iOS hit Threes called out 1024 and 2048as "rip-offs" in a blog post on Friday.

"It’s still hard to address the world’s response with something beyond a wide-eyed daze but essentially we couldn’t be more thrilled. Duh," the devs wrote on the website for Threes. "But there’s another side of that daze that we wish to talk about. The rip-offs."

They point directly at iOS game 1024, which released 21 days after Threes and 2048, a free, open source browser game that released about a week and a half after 1024.

1024 changes the gameplay by moving cards their full possible distance and adding "stones" as obstacles to move cards around. 2048 eliminates the stones, and, being open source, has spawned spinoffs including Numberwang 2048 and DOGE2048.

Gabriele Cirulli, 2048's creator,acknowledges similarities to Threes in a note on the game's site: "Created by Gabriele Cirulli. Based on 1024 by Veewo Studio and conceptually similar to Threes by Asher Vollmer." It also added an announcement:

"NOTE: This site is the official version of 2048. You can play it on your phone via http://git.io/2048. All other apps or sites are derivatives or fakes, and should be used with caution."

"It’s all in good fun, at least we’d like to think so, but try as our logical brains might, we still got the same 'cloning feeling,'" Vollmer wrote. "Especially when people called Threes, a game we poured over for nearly a year and a half, a clone of 2048."

Vollmer then writes why the team thinks Threes is the better game, citing their 14-month development time and thoughts that 2048 is a "simpler, easier" game.

This is far from the first time that clones of games have been an issue. One notable example is when 2013 iOS game Ridiculous Fishing was based on the developers' previous title, Radical Fishing. Ridiculous Fishing competed with Ninja Fishing, which cloned Radical Fishing and made it to market first.

As of this writing, Cirulli has not commented on the blog post. He has given interview to outlets such as the Los Angeles Timesand CNBCwith no mention of Threes (The Los Angeles Timeslater followed up with with the Threes developers' points of view.)